The rotary encoder series ECI 4000/EBI 4000 is a modular device without integral bearing and with a 90 mm hollow shaft. It enables the user to replace the conventional toothed-belt drive for coupling a motor feedback system to torque motors.
With fewer components, these rotary encoders provide wear-free operation. They open up new applications for inductive rotary encoders, for example, on highly dynamic motors, drive modules and machine components that require a corresponding hollow shaft in the encoder.
The singleturn version of the ECI 4000 features resolution of 20 bits. As an alternative, the EBI 4000 offers a multiturn variant with a revolution counter option with resolution of 16 bits and that is backed up by an external battery buffer. The inductive rotary encoders consist of a scanning unit and the scale drum.
The scanning is performed through an all-round scanning. In this setup, the complete graduation structure of the scale drum (rotor) with the associated scanning band of the scanning unit (stator) is involved in obtaining the position signal. In this way, the rotary encoder evaluates two incremental scanning tracks of differing periodicity. This scanning principle has a positive effect on the mounting tolerances and the positioning accuracy. Additionally, over the entire velocity range up to 6000 rpm, it largely compensates position error arising from a rotational center offset of the measured shaft.
The inductive rotary encoders ECI 4000 and EBI 4000 are equipped with the digital EnDat 2.2 interface.
Certification for SIL 2 applications in compliance with EN 61508 is being planned for the encoders. By employing additional measures in the subsequent electronics, users can raise the security level of the EnDat 2.2 devices to SIL 3. The relevant fault exclusion criteria for a safe mechanical connection are of course part of the certification.
The encoders are designed for easy installation and integration into the applications of motors and machines. Among other things, they fulfill protection class of IP40 for this. Thanks to an external and an internal centering diameter on the scanning unit and scale drum respectively, they can be mounted quickly without any special tools for adjusting and testing and immediately put into operation. An application-specific axial offset of the scale drum to the scanning unit is tolerated in a range of ±1.5 mm. The maximum drive shaft runout tolerance is 0.2 mm.
The operating temperature range for encoders with EnDat 2.2 interface is up to +115 °C. Vibration resistance is 400 m/s² for the stator and 600 m/s² for the rotor in accordance with EN 60068-2-6.
HEIDENHAIN Corp.
heidenhain.us
Filed Under: Machine tools + subtractive manufacturing, Encoders (rotary) + resolvers, Motors (direct-drive) + frameless motors